@sibo1952
Welcome to CAF, sibo1952! Lol! I hate the expression, “Everything is (Things are) relative,” but, sometimes that’s a pretty apt summation.
Don’t forget that the lesser sins are venial, and the sins of grave matter are the mortal sins, but there are three conditions: the sin actually must be of grave or mortal matter, you must be aware that it’s a mortal sin, and you must choose to do it.
I was sidetracked for awhile, came back, and now see that @Bithynian uses “It depends,” to describe your situation—in a similar category to “Everything is (Things are) relative.” As far as your specific question regarding excommunication, do you see now that you do not meet the criteria above? So excommunication was/is not a possibility, the way I understand our faith.
Sometimes citizens are given a choice of Party A’s brand of socialism, or Party B’s brand of socialism. (Other choices might be equally despicable.) Put very simply, the Church promotes the freedom of each individual, not the quashing and squashing of one’s mind, body, spirit, and property. That’s when the “It depends” and “Everything is (Things are) relative” comes into play.
You’re not helping yourself or your country if you fail to vote when you have the opportunity. You must vote your conscience: weigh the alternatives and vote the way you think is best for the people in your country, for both the immediate future and the distant future. Many times, we are forced to choose the lesser of two evils. So, “it depends,” because sometimes “things really are relative.”
However, any time that you would choose to vote for a government that would strip freedom from all but a few individuals, and you knew that you would be one of those government ruling elite, at the expense of your fellow man, you would be inherently wrong.
Your question is an interesting one, and apropos in this particular reality moment of world history. Most of us mean well, but precise meanings are lost when we type and you don’t hear our inflection when we voice our opinions. Misunderstandings abound, and few of us have studied the Church like our priests have, so please don’t rely upon our answers, but do talk to your priest and unload this burden. Ahem. Father knows best!